// profile2.js 
 // 写法二：一次性导出多个变量 
 var name = '牛牛' 
 var age = 20 
 var sex = '男' 
 export { name, age, sex } 
 // 导出时可以使用 as 关键字更改变量名 
 export { name as p2Name, age as p2Age, sex as p2Sex}